Take a visitor on a stroll through your native city and you are made all too aware of how we take the familiar for granted, even when the familiar consists of buildings as extraordinary as some of those pictured here: the Post Office Tower (since renamed in honour of the privatised British Telecom), Centre Point, Lloyd's and the Midland Grand Hotel at St Pancras.

Etienne Clement is a Parisian photographer, settled recently in London, who prowls the capital at night. He sees London as few indigenous nighthawks do. His shot of the central shaft of the Telecom Tower is at once familiar yet oddly unsettling. The viewer blinks twice at this curiously-angled image before recognising the steel and glass outline of the famous 620-ft radio, telephone and TV transmitter.

Clement's chiaroscuro approach is not perverse: it is both very beautiful (the quality of his highly crafted photographic prints is a joy) and reminds us that this is a building most of us know only as an abstract. If you walk past, you will surely miss it. Shooting up from a concrete base in the middle of an anonymous block of Government buildings, the tower, as thin as Trish Goff, shoots obscurely into the West End sky. The only way to see it in all its elongated glory is from unlikely, neck-straining angles and from miles away.

Or at night; for it is at night that many overlooked buildings come to life and josh lazy eyes into focus. There is little doubt that the London skyline, or the skyscape of most modernised cities, looks best when the sun has dropped over the concrete horizon and electric light animates streets and embankments, rivers, domes and towers. In recent weeks, Londoners have been rewarded with peerless views of St Paul's Cathedral, the River Thames and the City from the glamorous new restaurant crowning the reinvigorated Oxo Building on the South Bank, between the National Theatre and Blackfriars Bridge (see p50). It is worth the price of a chic cocktail for this view alone; we gawp like schoolchildren on our first trip to the Tower of London.

Night works a special magic, igniting mysterious windows secreted amongst the upper storeys of abandoned warehouses, seedy hotels and offices well past their rental date. Who could possibly be working this late at night in that sad early Sixties office block? Which budding poet or breadline hack is scribbling in that attic above a cornice line defaced by flea- ridden feral pigeons?

Doorways that by day seem innocuous when closed to Soho streets, spell guilt and furtiveness by night as they spill lurid light from bare 60-watt red bulbs onto narrow pavements. Night illuminates the city in ways that render beautiful battered buildings and worn faces - even the deregulated, smoke-spewing double- deckers that foul London streets. In Clement's lens, St Pancras (designed by Sir George Gilbert Scott) becomes the stuff of bat-winged Gothic horror, whilst the Lloyd's building in Leadenhall Street, by Richard Rogers, could be a set-design from Metropolis, and Centre Point, a megalomaniacal concrete bee-hive.

There are photographers employed to flatter architects' new glass buildings by photographing them at night. But Etienne Clement does not give the night-time city a romantic gloss; he gets under its worn and familiar skin and takes us on a film-noirish adventure.